1. Field of the Invention
The present invention relates to a frequency counter circuit and, more particularly, to an addressing type frequency counter circuit.
2. Description of Related Art
Currently, CPU is composed of a control unit, an arithmetic and logic unit, and registers. The control unit used to control data transmission of each unit in CPU. Arithmetic and logic unit is composed of an arithmetic unit and a logic unit, for performing arithmetic operation (sum, subtract, multiply, and divide) and logic operation (AND, OR, and NOT) and outputting operation result of the arithmetic and logic unit to the registers. Arithmetic and logic unit comprises a frequency counter wherein as CPU receives a clock from external device, the frequency counter begins counting the clock and outputting a result to CPU. Using CPU to set address to the frequency counter not only wastes the energy but also decreases work efficiency. Therefore, it is desirable to provide an improved circuit to mitigate and/or obviate the aforementioned problems.